docs: def get_competitions(self, tournament=1):
          """Retrieves information about all competitions
  
          Args:
              tournament (int, optional): ID of the tournament, defaults to 1
  
          Returns:
              list of dicts: list of rounds
  
              Each round's dict contains the following items:
  
                  * datasetId (`str`)
                  * number (`int`)
                  * openTime (`datetime`)
                  * resolveTime (`datetime`)
                  * participants (`int`): number of participants
                  * prizePoolNmr (`decimal.Decimal`)
                  * prizePoolUsd (`decimal.Decimal`)
                  * resolvedGeneral (`bool`)
                  * resolvedStaking (`bool`)
                  * ruleset (`string`)
  
          Example:
              >>> NumerAPI().get_competitions()
              [
               {'datasetId': '59a70840ca11173c8b2906ac',
                'number': 71,
                'openTime': datetime.datetime(2017, 8, 31, 0, 0),
                'resolveTime': datetime.datetime(2017, 9, 27, 21, 0),
                'participants': 1287,
                'prizePoolNmr': Decimal('0.00'),
                'prizePoolUsd': Decimal('6000.00'),
                'resolvedGeneral': True,
                'resolvedStaking': True,
                'ruleset': 'p_auction'
               },
                ..
              ]
          """
          self.logger.info("getting rounds...")
  
          query = '''
              query($tournament: Int!) {
                rounds(tournament: $tournament) {
                  number
                  resolveTime
                  datasetId
                  openTime
                  resolvedGeneral
                  resolvedStaking
                  participants
                  prizePoolNmr
                  prizePoolUsd
                  ruleset
                }
              }
          '''
          arguments = {'tournament': tournament}
          result = self.raw_query(query, arguments)
          rounds = result['data']['rounds']
          # convert datetime strings to datetime.datetime objects
          for r in rounds:
              utils.replace(r, "openTime", utils.parse_datetime_string)
              utils.replace(r, "resolveTime", utils.parse_datetime_string)
              utils.replace(r, "prizePoolNmr", utils.parse_float_string)
              utils.replace(r, "prizePoolUsd", utils.parse_float_string)
          return rounds